J/ApJ/680/1295 Optical spectroscopy of Cha-II PMS stars (Spezzi+, 2008)
The young population of the Chamaeleon II dark cloud.
Spezzi L., Alcala J.M., Covino E., Frasca A., Gandolfi D., Oliveira I.,
Chapman N., Evans II N.J., Huard T.L., Jorgensen J.K., Merin B.,
Stapelfeldt K.R.
<Astrophys. J., 680, 1295-1318 (2008)>
=2008ApJ...680.1295S 2008ApJ...680.1295S
ADC_Keywords: Molecular clouds ; Stars, pre-main sequence ; Equivalent widths
Keywords: circumstellar matter - infrared: stars -
planetary systems: protoplanetary disks - stars: formation -
stars: low-mass, brown dwarfs - stars: pre-main sequence
Abstract:
We discuss the results of the optical spectroscopic follow-up of
pre-main-sequence (PMS) objects and candidates selected in the
Chamaeleon II dark cloud based on data from the Spitzer Legacy survey
"From Molecular Cores to Planet Forming Disks" (c2d) and from previous
surveys. Our sample includes both objects with infrared excess
selected according to c2d criteria and referred to as young stellar
objects and other cloud members and candidates selected from
complementary optical and near-infrared data. We characterize the
sample of objects by deriving their physical parameters.
Description:
Multiobject spectroscopy was performed with FLAMES at the ESO VLT-UT2
during two observing runs in visiting mode. The first run was in 2006
February, while the second one was in 2007 February.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 82 63 Spectral types and line widths for
pre-main-sequence objects and candidates in Cha-II
table4.dat 77 63 Physical parameters for pre-main-sequence
objects and candidates in Cha-II
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See also:
J/A+A/399/995 : SOFI and ISOCAM observations of Cha II (Persi+, 2003)
J/A+A/470/281 : WFI optical photometry in Cha II dark cloud (Spezzi+, 2007)
J/ApJ/676/427 : MIPS and IRAC Chamaeleon II PMS data (Alcala+, 2008)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- [ASC2008] Sequential number
4- 33 A30 -- Name Name
34 A1 --- n_SpT [eghijl] Note about spectral type origin (1)
36- 39 A4 --- FLAMES FLAMES instrument (GIRAFFE-MEDUSA or UVES)
41 I1 --- Sp1 ? Spectrum number
42 A1 --- --- [/]
43 I1 --- Sp2 ? Second spectrum number
45- 47 I3 --- S/N ? Signal-to-noise ratio
48 A1 --- --- [/]
49- 51 I3 --- S/N2 ? Second signal-to-noise ratio
53- 55 A3 --- PMS PMS object (PMS) or candidate (CND) status
56 A1 --- n_PMS [fk] Note about PMS status (4)
58- 61 A4 --- SpT MK spectral type (5)
63- 65 I3 0.1nm EWHa ? Hα equivalent width (6)
67- 70 F4.2 0.1nm EWLi ? Lithium equivalent width
72- 74 I3 km/s FWHa10 ? Full width of Hα measured at 10% of
the peak intensity
76- 82 E7.2 solMass/yr dM/dt ? Mass loss
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Note (1): Notes as follows:
e = Spectral type corresponding to the best-fitting SED model by
Robitaille et al. (2006ApJS..167..256R 2006ApJS..167..256R; see Paper I, Alcala
et al., 2008, Cat. J/ApJ/676/427)
g = Spectral type by Jayawardhana & Ivanov (2006ApJ...647L.167J 2006ApJ...647L.167J)
h = Spectral type and EWHa by Alcala et al. (2006A&A...453L...1A 2006A&A...453L...1A)
i = Given the low S/N of our FLAMES spectrum, we adopted for this
object the spectral type by Barrado y Navascues & Jayawardhana
(2004ApJ...615..840B 2004ApJ...615..840B)
j = Spectral type and EWHa by Hughes & Hartigan (1992AJ....104..680H 1992AJ....104..680H)
l = Spectral type by Hartigan (1993AJ....105.1511H 1993AJ....105.1511H)
Note (4): Note on PMS as follows:
f = Cha II member first confirmed in this work
k = Li I absorption at lambda=6707.8Å detected for the first time
Note (5): Spectral type of the candidate corresponding to the estimated
temperature (see Sec. 4.2). Spectral type equal to "C" stands for
"continuum-type object" (see Sec. 4.1).
Note (6): The EWHa of candidates and objects lacking spectroscopy is
estimated from the WFI (Hα12-Hα7) color index (see Sec. 8).
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- [ASC2008] Sequential number
4- 33 A30 -- Name Name
34 A1 --- Note [bc] Note on object (1)
36- 39 I4 K Teff ? Effective temperature
41- 43 I3 K e_Teff ? rms uncertainty on Teff
45- 49 F5.2 mag AV ? Absorption in V band
51- 54 F4.2 mag e_AV ? rms uncertainty on AV
56- 60 F5.2 [solLum] logL ? Luminosity
62- 65 F4.2 [solLum] e_logL ? rms uncertainty on logL
67- 71 F5.2 solRad Rad ? Stellar radius
73- 76 F4.2 solRad e_Rad ? rms uncertainty on Rad
77 A1 --- u_Rad [a] logL and Rad are estimates (1)
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Note (1): Notes as follows:
b = Physical parameters have been estimated as explained in Sec. 4.7
c = Object classified as "continuum-type" (see Sec. 4.1)
a = Estimates by assuming the Cha II distance of 178pc (see also Sec. 4.5)
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History:
From electronic version of the journal
References:
Alcala et al., Paper I 2008ApJ...676..427A 2008ApJ...676..427A, Cat. J/ApJ/676/427
(End) Patricia Vannier [CDS] 19-Aug-2009